1. Field of the Invention
The present invention relates to a vehicle shift control apparatus that is operable in a vehicle having a plurality of driving force modes in which an engine generates driving force in response to an accelerator operation and, for an automatic transmission, an automatic shift mode and a temporary manual shift mode in which a manual shift mode is temporarily used during driving in the automatic shift mode.
2. Description of the Related Art
Recently, automatic transmissions for a vehicle that are operable in a so-called temporary manual shift mode have been developed and practically used. The automatic transmission in such a mode allows a driver temporarily to perform an up-shift or a down-shift thereof by pressing an up-shift switch or a down-shift switch fitted in a steering wheel or the like with a select lever of the transmission being positioned in the drive (D) range. For example, Japanese Unexamined Patent Application Publication No. 2006-97789 discloses a shift control apparatus for a continuously variable transmission which is operable in; an automatic shift mode in which a gear ratio of the continuously variable transmission is automatically set; and a temporary manual shift mode in which a gear ratio of the continuously variable transmission can be selected from among a plurality of predetermined fixed gear ratios via the operation of a shift switch during driving in an automatic shift mode. When the temporary manual shift mode is switched to the automatic shift mode due to a cancel operation, the shift control apparatus sets a target speed of the engine on the basis of the driving condition of the vehicle and changes the gear ratio gradually at each calculation step so that the engine speed can change continuously to the targeted speed.
Meanwhile, there has been developed and practically used a vehicle that can be driven in a plurality of driving force modes in which the engine generates driving force in response to an accelerator operation. These driving force modes include a comfort-oriented and economy-oriented driving force mode and a sport-oriented and maneuverability-oriented driving force mode. When one of the modes is selected in order to satisfy driver's requirements, the engine is operated according to driving force characteristics corresponding to the selected mode. If a technology including a temporary manual shift mode such as disclosed in the Japanese Unexamined Patent Application Publication No. 2006-97789 is applied to such a vehicle having a plurality of driving force modes, shift characteristics are required that allow the vehicle to be driven under a driving condition desired by a driver.